<template>
  <div class="article-container">
    <!-- 导航栏 -->
    <van-nav-bar class="page-nav-bar"
      left-arrow
      title="社交头条"
      @click-left="$router.back()"></van-nav-bar>
    <!-- /导航栏 -->

    <div class="main-wrap">
      <!-- 加载中 -->
      <div v-if="loading"
        class="loading-wrap">
        <van-loading color="#3296fa"
          vertical>加载中</van-loading>
      </div>
      <!-- /加载中 -->

      <!-- 加载完成-文章详情 -->
      <div v-else-if="article.title"
        class="article-detail">
        <!-- 文章标题 -->
        <h1 class="article-title">{{article.title}}</h1>
        <!-- /文章标题 -->

        <!-- 用户信息 -->
        <van-cell class="user-info"
          center
          :border="false">
          <van-image class="avatar"
            slot="icon"
            round
            fit="cover"
            :src="article.aut_photo " />
          <div slot="title"
            class="user-name">{{article.aut_name}}</div>
          <div slot="label"
            class="publish-date">{{article.pubdate | relativeTime}}</div>
          <!-- 用户关注状态 -->
          <!--
            模板中的 $event 是事件参数
            当我们传递给子组件的数据既要使用还要修改。
              传递：props
                :is-followed="article.is_followed"
              修改：自定义事件
                @update-is_followed="article.is_followed = $event"
            简写方式：在组件上使用 v-model
              value="article.is_followed"
              @input="article.is_followed = $event"

            如果需要修改 v-model 的规则名称，可以通过子组件的 model 属性来配置修改

            一个组件上只能使用一次 v-model，
            如果有多个数据需要实现类似于 v-model 的效果，咋办？
            可以使用属性的 .sync 修饰符。
           -->
          <follow-user class="follow-btn"
            v-model="article.is_followed"
            :user-id="article.aut_id"></follow-user>

          <!-- <van-button v-if="article.is_followed"
            class="follow-btn"
            round
            size="small"
            @click="onFollow"
            :loading='isFollowLoading'>已关注</van-button>
          <van-button v-else
            class="follow-btn"
            type="info"
            color="#3296fa"
            round
            size="small"
            icon="plus"
            @click="onFollow"
            :loading='isFollowLoading'>关注</van-button> -->

        </van-cell>
        <!-- /用户信息 -->

        <!-- 文章内容 -->
        <div class="article-content markdown-body"
          ref="article-content"
          v-html="article.content"></div>
        <van-divider>正文结束</van-divider>

        <!-- 文章评论列表 -->
        <comment-list :source="article.art_id"
          :list="commentList"
          @onload-success="totalCommentCount=$event.total_count"
          @click-reply="onClickReply">

        </comment-list>

        <!-- 底部区域 -->
        <div class="article-bottom">
          <van-button class="comment-btn"
            type="default"
            round
            size="small"
            @click="isPostShow = true">写评论</van-button>
          <van-icon name="comment-o"
            :info="totalCommentCount"
            color="#777" />

          <!-- 收藏组件 -->
          <colecte-article v-model="article.is_collected"
            :article-id="article.art_id"
            class="btn-item"></colecte-article>

          <!-- <van-icon color="#777"
        name="star-o" /> -->
          <!-- 点赞组件 -->
          <like-article class="btn-item"
            v-model="article.attitude"
            :article-id="article.art_id"></like-article>
          <!-- <van-icon color="#777"
        name="good-job-o" /> -->
          <van-icon name="share"
            color="#777777"></van-icon>
        </div>
        <!-- /底部区域 -->

        <!-- 评论弹出层 -->
        <!-- 弹出层是懒渲染的：只有在第一次展示的时候才会渲染里面的内容，之后它的关闭和显示都是在切换内容的显示和隐藏 -->
        <van-popup v-model="isPostShow"
          position="bottom"
          :style="{ height: '30%' }"
        >

          <!-- 弹出层内部组件 -->
          <comment-post :target="article.art_id"
            @post-success="onPostSuccess"></comment-post>
        </van-popup>
      </div>

      <!-- /加载完成-文章详情 -->

      <!-- 加载失败：404 -->
      <div v-else-if="errStatus===404"
        class="error-wrap">
        <van-icon name="failure" />
        <p class="text">该资源不存在或已删除！</p>
      </div>
      <!-- /加载失败：404 -->

      <!-- 加载失败：其它未知错误（例如网络原因或服务端异常） -->
      <div v-else
        class="error-wrap">
        <van-icon name="failure" />
        <p class="text">内容加载失败！</p>
        <van-button class="retry-btn">点击重试</van-button>
      </div>
      <!-- /加载失败：其它未知错误（例如网络原因或服务端异常） -->
    </div>

    <!-- 评论回复 -->
    <van-popup v-model="isReplyShow"
      position="bottom"
       :style="{ height: '95%' }"
     >
      <!-- 评论回复 -->
<!-- v-if 条件渲染 true：渲染元素节点 false：不渲染 -->
      <comment-reply v-if="isReplyShow" :comment="currentComment"
        @close="isReplyShow = false"></comment-reply>
    </van-popup>
    <!-- /评论回复 -->

  </div>
</template>

<script>

import { getArticleById } from '@/api/article.js'

import { ImagePreview } from 'vant'
import FollowUser from '@/components/follow-user/FollowUser.vue'
import ColecteArticle from '@/components/colecte-article/ColecteArticle.vue'
import LikeArticle from '@/components/like-article/LikeArticle.vue'
import CommentList from '@/components/comments/CommentList.vue'
import CommentPost from '@/components/comments/comment-post.vue'
import CommentReply from './components/comment-reply.vue'

export default {
  name: 'ArticleDetails',

  // 给所有后代组件提供数据
  provide: function () {
    return {
      articleId: this.articleId
    }
  },
  props: {
    // 文章id
    articleId: {
      type: [Number, String],
      required: true
    }
  },
  data () {
    return {
      // 文章详情
      article: [],
      loading: true, // 加载中的 loading 状态
      errStatus: 0, // 失败的状态码
      isFollowLoading: false, // 关注用户时的loading 状态
      totalCommentCount: 0, // 控制评论数量
      // 控制评论弹出层
      isPostShow: false,
      // 评论列表
      commentList: [],
      isReplyShow: false, // 控制评论回复的弹出层
      currentComment: {} // 评论对象的信息
    }
  },
  created () {
    this.loadArticle()
  },
  methods: {
    // 获取文章详情数据
    async loadArticle () {
      // 展示 loading 加载中
      this.loading = true
      try {
        const { data: res } = await getArticleById(this.articleId)
        console.log(res)
        // 数据驱动视图这件事儿不是立即的
        this.article = res.data
        // 请求成功关闭loading
        // this.loading = false

        // 初始化图片点击预览
        setTimeout(() => {
          // console.log(this.$refs['article-content'])
          this.previewImage()
        }, 0)
      } catch (err) {
        // this.loading = false

        if (err.response && err.response.status === 404) {
          this.errStatus = 404
        }
        console.log('获取数据失败', err)
      }
      this.loading = false
    },
    // 图片预览
    previewImage () {
      // 得到所有的img 节点
      const articleContent = this.$refs['article-content']
      // console.log(articleContent)

      const imgs = articleContent.querySelectorAll('img')
      console.log(imgs)

      // 获取所有img 地址
      const images = []
      imgs.forEach((img, index) => {
        images.push(img.src)

        // 点击每个 img 图片预览

        img.onclick = () => {
          ImagePreview({
            // 预览图片的地址数组
            images,
            // 起始位置 从0 开始
            startPosition: index
          })
        }
      })
    },

    // 发布成功后处理逻辑
    onPostSuccess (data) {
      // 关闭弹层
      this.isPostShow = false
      // 将发布的内容显示到列表顶部

      this.commentList.unshift(data.new_obj)
    },

    onClickReply (comment) {
      console.log(comment)
      this.currentComment = comment

      // 显示评论回复弹出层
      this.isReplyShow = true
    }

  },
  components: {
    FollowUser,
    ColecteArticle,
    LikeArticle,
    CommentList,
    CommentPost,
    CommentReply

  }
}
</script>

<style lang="less" scoped>

@import './github-markdown.css';

.article-container {
 /deep/ .van-icon-arrow-left{
    color: #ccc;
  }
  .main-wrap {
    position: fixed;
    left: 0;
    right: 0;
    top: 92px;
    bottom: 88px;
    overflow-y: scroll;
    background-color: #fff;
  }
  .article-detail {
    .article-title {
      font-size: 40px;
      padding: 50px 32px;
      margin: 0;
      color: #3a3a3a;
    }

    .user-info {
      padding: 0 32px;
      .avatar {
        width: 70px;
        height: 70px;
        margin-right: 17px;
      }
      .van-cell__label {
        margin-top: 0;
      }
      .user-name {
        font-size: 24px;
        color: #3a3a3a;
      }
      .publish-date {
        font-size: 23px;
        color: #b7b7b7;
      }
      .follow-btn {
        width: 170px;
        height: 58px;
      }
    }

    .article-content {
      padding: 55px 32px;
      /deep/ p {
        text-align: justify;
      }
    }
  }

  .loading-wrap {
    padding: 200px 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #fff;
  }

  .error-wrap {
    padding: 200px 32px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: #fff;
    .van-icon {
      font-size: 122px;
      color: #b4b4b4;
    }
    .text {
      font-size: 30px;
      color: #666666;
      margin: 33px 0 46px;
    }
    .retry-btn {
      width: 280px;
      height: 70px;
      line-height: 70px;
      border: 1px solid #c3c3c3;
      font-size: 30px;
      color: #666666;
    }
  }

  .article-bottom {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    justify-content: space-around;
    align-items: center;
    box-sizing: border-box;
    height: 88px;
    border-top: 1px solid #d8d8d8;
    background-color: #fff;
    .comment-btn {
      width: 282px;
      height: 46px;
      border: 2px solid #eeeeee;
      font-size: 30px;
      line-height: 46px;
      color: #a7a7a7;
    }

    .van-button--normal{
      padding: 0;
    }
  /deep/ .van-icon {
      font-size: 40px;
      .van-info {
        font-size: 16px;
        background-color: #e22829;
      }
    }
  }
}
</style>
